ΔE 9.6, close: similar, with a visible difference side by side. JGSD Brown is a little darker than Granite Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). JGSD Brown is a little darker than Granite Grey.
The same difference applies the other way round: Granite Grey is a little lighter.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Granite Grey on the colour wheel See JGSD Brown on the colour wheel
All matches: Granite Grey equivalents · JGSD Brown equivalents